Initial commit of git plugin

build.sbt

@@ -0,0 +1,11 @@
+sbtPlugin := true
+
+resolvers += "jgit-repo" at "http://download.eclipse.org/jgit/maven"
+
+name := "sbt-git-plugin"
+
+organization := "com.typesafe"
+
+version := "0.1"
+
+libraryDependencies += "org.eclipse.jgit" % "org.eclipse.jgit.pgm" % "1.1.0.201109151100-r"

src/main/scala/GitPlugin.scala

@@ -0,0 +1,72 @@
+package com.typesafe.git 
+
+import sbt._
+import Keys._
+import org.eclipse.jgit.pgm.{Main=>JGit}
+
+/** Keys relative to using git from SBT */
+object GitKeys {
+  val gitRemoteRepo = SettingKey[String]("git-remote-repo", "The remote git repository assoicated with this project") 
+  val gitRunner = TaskKey[GitRunner]("git-runner", "The mechanism used to run git in the current build.")
+}
+
+/** This plugin has all the basic 'git' functionality for other plugins. */
+object GitPlugin extends Plugin {
+  import GitKeys._
+  // TODO - Should we embedd everywhere like this?
+  override val settings = Seq(
+    gitRunner in ThisBuild := ConsoleGitRunner
+    // TODO - add an inputtask that can run git inside SBT.
+  )
+
+  def useJGit = gitRunner in ThisBuild := JGitRunner
+}
+
+
+/** An interface to run git commands. */
+trait GitRunner {
+  /** Akin to running 'git {args}' with a given working directory `cwd` and logger. */
+  def apply(args: String*)(cwd: File, log: Logger): Unit
+  /** Commits all local changes and pushes the new commit to a remote repository. */
+  def commitAndPush(msg: String, tag: Option[String] = None)(repo: File, log: Logger) {
+    apply("add", ".")(repo, log)
+    apply("commit", "-m", msg, "--allow-empty")(repo, log)
+    for(tagString <- tag) apply("tag", tagString)(repo, log)
+    push(repo, log)
+  }
+  /** Pushes local commits to the remote branch. */
+  def push(cwd: File, log: Logger) = apply("push")(cwd, log)
+  /** Pulls remote changes into the local branch. */
+  def pull(cwd: File, log: Logger) = apply("pull")(cwd, log)
+  /** Updates the cwd from a remote branch. If the local git repo doesn't exist, will clone it into existence. */
+  def updated(remote: String, branch: Option[String], cwd: File, log: Logger): Unit =
+      if(cwd.exists) pull(cwd, log)
+      else branch match {
+        case None => apply("clone", remote, ".")(cwd, log)
+        case Some(b) => apply("clone", "-b", b, remote, ".")(cwd, log)
+      }
+}
+
+/** A mechanism to run GIT using the pure java JGit implementation. */
+object JGitRunner extends GitRunner {
+  override def apply(args: String*)(cwd: File, log: Logger): Unit =
+    // TODO -  Can we just assume the .git repo? I hope so....
+    JGit.main((Seq("--git-dir", cwd.getAbsolutePath + "/.git") ++ args).toArray)  
+  override def toString = "jgit"  
+}
+
+/** A mechanism of running git that simply shells out to the console. */
+object ConsoleGitRunner extends GitRunner {
+  // TODO - Something less lame here.
+  private lazy val cmd = if(System.getProperty("os.name").toLowerCase().contains("windows")) "git.exe" else "git"
+  override def apply(args: String*)(cwd: File, log: Logger): Unit = {
+      IO.createDirectory(cwd)
+      val full = "git" +: args
+      log.info(cwd + "$ " + full.mkString(" "))
+      val code = Process(full, cwd) ! log
+      if(code != 0) error("Nonzero exit code for git " + args.take(1).mkString + ": " + code)
+  }
+  override def toString = "git"
+}
+
+